Clarke, who hit 259 not out in the drawn series opener, finished the day unbeaten on 224 from 243 deliveries, with 39 4s and one 6. Australia's total after 86.5 overs was an imposing 482 for five, with opener David Warner (119) and veteran Michael Hussey (103) also compiling centuries and hitting four 6s apiece.
When Clarke arrived at the crease, South Africa, who had lost the toss, had struck early to have the home side on 55 for three. Following failures for Ed Cowan, Rob Quiney and Ricky Ponting, though, Warner and Clarke led the fightback superbly. Their game-turning stand was surely eased by the injury enforced departure of Jacques Kallis, not to mention Vernon Philander pulling out before the start of play.
An MRI scan after the close of play revealed that Kallis had suffered a grade one hamstring strain, and he will not be able to bowl again in the match although he has been deemed fit enough to bat. Kallis had taken the first wicket of the day, trapping Cowan, the one-time Scottish Saltires overseas player, plumb in front of the stumps and claiming a return catch after the ball hit the bat, with the latter dismissal taking precedence under the laws of the game.